He served the Penobscot Indian Nation as its representative to the state legislature during its last session.
Sockalexis reportedly died sunday at a Bangor hospital at the age of 60.
Sockalexis made it his mission to try and preserve the Penobscot language: last year, he sponsored a bill to allocate money for a language preservation fund.
A funeral service for Sockalexis has been scheduled for Wednesday at St. Ann’s Catholic Church on Indian Island.
Sockalexis leaves behind a wife and three children.